From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4E7E7C433E0 for ; Mon, 8 Mar 2021 10:51:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0FC05651FC for ; Mon, 8 Mar 2021 10:51:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229754AbhCHKu6 (ORCPT ); Mon, 8 Mar 2021 05:50:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37392 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229671AbhCHKue (ORCPT ); Mon, 8 Mar 2021 05:50:34 -0500 Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B1E13C06174A for ; Mon, 8 Mar 2021 02:50:33 -0800 (PST) Received: by mail-wm1-x331.google.com with SMTP id t5-20020a1c77050000b029010e62cea9deso3503369wmi.0 for ; Mon, 08 Mar 2021 02:50:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:cc:references:from:autocrypt:subject:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=SNe5gfcrhW0ZGXBn4AR+5RuHI1sn/KRN4BXzQ2wl5UU=; b=HOOVneGmV/CufFGkVyxCH2r/u+eVxGQod32GK2yIlNBUiEJPNjQvKwLyUnjgiVaALj xzlpMydUIEJn+J34OdrQnrEeeOEVMs3hp0nfJnkY6sC13NjeM4xs+MJQTv7KjMFSMa40 V2wf+45f6RvJ6ygwq90uKaGt5D3T1RAkZycd3VQDMR+KBvSOlV2QUE5YPzFmzc2ev4J2 J4HBNBNn1w2b2558un/SCK01KrD4IBKgo+zS3D+s37t0DPgMlEqn9KiWsn9iADU0xABW 1ul6xFpfWSK/vfj2/4IcL2ybqIPUq7o4/el/zGi78oXt7bwNp9jC11Nv7wxz5lFmVUav U0SA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:cc:references:from:autocrypt:subject :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=SNe5gfcrhW0ZGXBn4AR+5RuHI1sn/KRN4BXzQ2wl5UU=; b=bo6SZlKsLaqpVvp5y4M5Vli2zSNlxMqlMk2bVW4/PUygcIjHGB9pibrJUW8xqLylCI hR7TIJZp/Tngi6XmL1nYBwxjC5QRD8iFygZ/HaS+tCJCAXmwCAulg8aBgtAA7P6igL3v H/WveourQ5kfVFEAcXGKqx8hVoH0Iq6/rwU/DEJizIi9Jmb4vWnKeWtas6n5KF6L9xBA Bwrdj7sG0IJX2IuMlmIYWx/7hpFfEvCttee7/IGTPRPyn8bQN2KHG2VuSOeAv07Ov4j5 Fs+wdj2LN/MUaoXpnWN5TgJVQ42lwnqouL7Tx5ct9xEpXFaBdguE+LTPK1rveMIfKuJj X9AQ== X-Gm-Message-State: AOAM5317QZ+G5VJHrygWcn8f3b5LQA5OoMjP1F7cdmGVYS5L/CYzxXlM 3lsFgYQn0mJ2mQCc4XnleTT6wMtBgAxd6g== X-Google-Smtp-Source: ABdhPJxXq3Xj3dqQaG1cYeAsU0KMkIRiT/cC/mhcMG8lJ5jWf91RU2TDvngaNwVR5WWAHsJaereMmQ== X-Received: by 2002:a05:600c:614:: with SMTP id o20mr20861726wmm.66.1615200632499; Mon, 08 Mar 2021 02:50:32 -0800 (PST) Received: from [192.168.8.117] ([148.252.132.144]) by smtp.gmail.com with ESMTPSA id o20sm18343295wmq.5.2021.03.08.02.50.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 08 Mar 2021 02:50:32 -0800 (PST) To: yangerkun , axboe@kernel.dk Cc: io-uring@vger.kernel.org, yi.zhang@huawei.com, Matthew Wilcox References: <20210308065903.2228332-1-yangerkun@huawei.com> From: Pavel Begunkov Autocrypt: addr=asml.silence@gmail.com; prefer-encrypt=mutual; keydata= mQINBFmKBOQBEAC76ZFxLAKpDw0bKQ8CEiYJRGn8MHTUhURL02/7n1t0HkKQx2K1fCXClbps bdwSHrhOWdW61pmfMbDYbTj6ZvGRvhoLWfGkzujB2wjNcbNTXIoOzJEGISHaPf6E2IQx1ik9 6uqVkK1OMb7qRvKH0i7HYP4WJzYbEWVyLiAxUj611mC9tgd73oqZ2pLYzGTqF2j6a/obaqha +hXuWTvpDQXqcOZJXIW43atprH03G1tQs7VwR21Q1eq6Yvy2ESLdc38EqCszBfQRMmKy+cfp W3U9Mb1w0L680pXrONcnlDBCN7/sghGeMHjGKfNANjPc+0hzz3rApPxpoE7HC1uRiwC4et83 CKnncH1l7zgeBT9Oa3qEiBlaa1ZCBqrA4dY+z5fWJYjMpwI1SNp37RtF8fKXbKQg+JuUjAa9 Y6oXeyEvDHMyJYMcinl6xCqCBAXPHnHmawkMMgjr3BBRzODmMr+CPVvnYe7BFYfoajzqzq+h EyXSl3aBf0IDPTqSUrhbmjj5OEOYgRW5p+mdYtY1cXeK8copmd+fd/eTkghok5li58AojCba jRjp7zVOLOjDlpxxiKhuFmpV4yWNh5JJaTbwCRSd04sCcDNlJj+TehTr+o1QiORzc2t+N5iJ NbILft19Izdn8U39T5oWiynqa1qCLgbuFtnYx1HlUq/HvAm+kwARAQABtDFQYXZlbCBCZWd1 bmtvdiAoc2lsZW5jZSkgPGFzbWwuc2lsZW5jZUBnbWFpbC5jb20+iQJOBBMBCAA4FiEE+6Ju PTjTbx479o3OWt5b1Glr+6UFAlmKBOQCGwMFCwkIBwIGFQgJCgsCBBYCAwECHgECF4AACgkQ Wt5b1Glr+6WxZA//QueaKHzgdnOikJ7NA/Vq8FmhRlwgtP0+E+w93kL+ZGLzS/cUCIjn2f4Q Mcutj2Neg0CcYPX3b2nJiKr5Vn0rjJ/suiaOa1h1KzyNTOmxnsqE5fmxOf6C6x+NKE18I5Jy xzLQoktbdDVA7JfB1itt6iWSNoOTVcvFyvfe5ggy6FSCcP+m1RlR58XxVLH+qlAvxxOeEr/e aQfUzrs7gqdSd9zQGEZo0jtuBiB7k98t9y0oC9Jz0PJdvaj1NZUgtXG9pEtww3LdeXP/TkFl HBSxVflzeoFaj4UAuy8+uve7ya/ECNCc8kk0VYaEjoVrzJcYdKP583iRhOLlZA6HEmn/+Gh9 4orG67HNiJlbFiW3whxGizWsrtFNLsSP1YrEReYk9j1SoUHHzsu+ZtNfKuHIhK0sU07G1OPN 2rDLlzUWR9Jc22INAkhVHOogOcc5ajMGhgWcBJMLCoi219HlX69LIDu3Y34uIg9QPZIC2jwr 24W0kxmK6avJr7+n4o8m6sOJvhlumSp5TSNhRiKvAHB1I2JB8Q1yZCIPzx+w1ALxuoWiCdwV M/azguU42R17IuBzK0S3hPjXpEi2sK/k4pEPnHVUv9Cu09HCNnd6BRfFGjo8M9kZvw360gC1 reeMdqGjwQ68o9x0R7NBRrtUOh48TDLXCANAg97wjPoy37dQE7e5Ag0EWYoE5AEQAMWS+aBV IJtCjwtfCOV98NamFpDEjBMrCAfLm7wZlmXy5I6o7nzzCxEw06P2rhzp1hIqkaab1kHySU7g dkpjmQ7Jjlrf6KdMP87mC/Hx4+zgVCkTQCKkIxNE76Ff3O9uTvkWCspSh9J0qPYyCaVta2D1 Sq5HZ8WFcap71iVO1f2/FEHKJNz/YTSOS/W7dxJdXl2eoj3gYX2UZNfoaVv8OXKaWslZlgqN jSg9wsTv1K73AnQKt4fFhscN9YFxhtgD/SQuOldE5Ws4UlJoaFX/yCoJL3ky2kC0WFngzwRF Yo6u/KON/o28yyP+alYRMBrN0Dm60FuVSIFafSqXoJTIjSZ6olbEoT0u17Rag8BxnxryMrgR dkccq272MaSS0eOC9K2rtvxzddohRFPcy/8bkX+t2iukTDz75KSTKO+chce62Xxdg62dpkZX xK+HeDCZ7gRNZvAbDETr6XI63hPKi891GeZqvqQVYR8e+V2725w+H1iv3THiB1tx4L2bXZDI DtMKQ5D2RvCHNdPNcZeldEoJwKoA60yg6tuUquvsLvfCwtrmVI2rL2djYxRfGNmFMrUDN1Xq F3xozA91q3iZd9OYi9G+M/OA01husBdcIzj1hu0aL+MGg4Gqk6XwjoSxVd4YT41kTU7Kk+/I 5/Nf+i88ULt6HanBYcY/+Daeo/XFABEBAAGJAjYEGAEIACAWIQT7om49ONNvHjv2jc5a3lvU aWv7pQUCWYoE5AIbDAAKCRBa3lvUaWv7pfmcEACKTRQ28b1y5ztKuLdLr79+T+LwZKHjX++P 4wKjEOECCcB6KCv3hP+J2GCXDOPZvdg/ZYZafqP68Yy8AZqkfa4qPYHmIdpODtRzZSL48kM8 LRzV8Rl7J3ItvzdBRxf4T/Zseu5U6ELiQdCUkPGsJcPIJkgPjO2ROG/ZtYa9DvnShNWPlp+R uPwPccEQPWO/NP4fJl2zwC6byjljZhW5kxYswGMLBwb5cDUZAisIukyAa8Xshdan6C2RZcNs rB3L7vsg/R8UCehxOH0C+NypG2GqjVejNZsc7bgV49EOVltS+GmGyY+moIzxsuLmT93rqyII 5rSbbcTLe6KBYcs24XEoo49Zm9oDA3jYvNpeYD8rDcnNbuZh9kTgBwFN41JHOPv0W2FEEWqe JsCwQdcOQ56rtezdCJUYmRAt3BsfjN3Jn3N6rpodi4Dkdli8HylM5iq4ooeb5VkQ7UZxbCWt UVMKkOCdFhutRmYp0mbv2e87IK4erwNHQRkHUkzbsuym8RVpAZbLzLPIYK/J3RTErL6Z99N2 m3J6pjwSJY/zNwuFPs9zGEnRO4g0BUbwGdbuvDzaq6/3OJLKohr5eLXNU3JkT+3HezydWm3W OPhauth7W0db74Qd49HXK0xe/aPrK+Cp+kU1HRactyNtF8jZQbhMCC8vMGukZtWaAwpjWiiH bA== Subject: Re: [PATCH 1/2] io_uring: fix UAF for personality_idr Message-ID: Date: Mon, 8 Mar 2021 10:46:37 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.0 MIME-Version: 1.0 In-Reply-To: <20210308065903.2228332-1-yangerkun@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 08/03/2021 06:59, yangerkun wrote: > Loop with follow can trigger a UAF: > > void main() > { > int ret; > struct io_uring ring; > struct io_uring_params p; > int i; > > ret = io_uring_queue_init(1, &ring, 0); > assert(ret == 0); > > for (i = 0; i < 10000; i++) { > ret = io_uring_register_personality(&ring); > if (ret < 0) > break; > } > > ret = io_uring_unregister_personality(&ring, 1024); > assert(ret == 0); > } Matthew, any chance you remember whether idr_for_each tolerates idr_remove() from within the callback? Nothing else is happening in parallel. > ================================================================== > BUG: KASAN: use-after-free in radix_tree_next_slot > include/linux/radix-tree.h:422 [inline] > BUG: KASAN: use-after-free in idr_for_each+0x88/0x18c lib/idr.c:202 > Read of size 8 at addr ffff0001096539f8 by task syz-executor.2/3166 > > CPU: 0 PID: 3166 Comm: syz-executor.2 Not tainted > 5.10.0-00843-g352c8610ccd2 #2 > Hardware name: linux,dummy-virt (DT) > Call trace: > dump_backtrace+0x0/0x1d8 arch/arm64/kernel/stacktrace.c:132 > show_stack+0x28/0x34 arch/arm64/kernel/stacktrace.c:196 > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x110/0x164 lib/dump_stack.c:118 > print_address_description+0x78/0x5c8 mm/kasan/report.c:385 > __kasan_report mm/kasan/report.c:545 [inline] > kasan_report+0x148/0x1e4 mm/kasan/report.c:562 > check_memory_region_inline mm/kasan/generic.c:183 [inline] > __asan_load8+0xb4/0xbc mm/kasan/generic.c:252 > radix_tree_next_slot include/linux/radix-tree.h:422 [inline] > idr_for_each+0x88/0x18c lib/idr.c:202 > io_ring_ctx_wait_and_kill+0xf0/0x210 fs/io_uring.c:8429 > io_uring_release+0x3c/0x50 fs/io_uring.c:8454 > __fput+0x1b8/0x3a8 fs/file_table.c:281 > ____fput+0x1c/0x28 fs/file_table.c:314 > task_work_run+0xec/0x13c kernel/task_work.c:151 > exit_task_work include/linux/task_work.h:30 [inline] > do_exit+0x384/0xd68 kernel/exit.c:809 > do_group_exit+0xb8/0x13c kernel/exit.c:906 > get_signal+0x794/0xb04 kernel/signal.c:2758 > do_signal arch/arm64/kernel/signal.c:658 [inline] > do_notify_resume+0x1dc/0x8a8 arch/arm64/kernel/signal.c:722 > work_pending+0xc/0x180 > > Allocated by task 3149: > stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121 > kasan_save_stack mm/kasan/common.c:48 [inline] > kasan_set_track mm/kasan/common.c:56 [inline] > __kasan_kmalloc+0xdc/0x120 mm/kasan/common.c:461 > kasan_slab_alloc+0x14/0x1c mm/kasan/common.c:469 > slab_post_alloc_hook+0x50/0x8c mm/slab.h:535 > slab_alloc_node mm/slub.c:2891 [inline] > slab_alloc mm/slub.c:2899 [inline] > kmem_cache_alloc+0x1f4/0x2fc mm/slub.c:2904 > radix_tree_node_alloc+0x70/0x19c lib/radix-tree.c:274 > idr_get_free+0x180/0x528 lib/radix-tree.c:1504 > idr_alloc_u32+0xa8/0x164 lib/idr.c:46 > idr_alloc_cyclic+0x8c/0x150 lib/idr.c:125 > io_register_personality fs/io_uring.c:9512 [inline] > __io_uring_register+0xed8/0x1d9c fs/io_uring.c:9741 > __do_sys_io_uring_register fs/io_uring.c:9791 [inline] > __se_sys_io_uring_register fs/io_uring.c:9773 [inline] > __arm64_sys_io_uring_register+0xd0/0x108 fs/io_uring.c:9773 > __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline] > invoke_syscall arch/arm64/kernel/syscall.c:48 [inline] > el0_svc_common arch/arm64/kernel/syscall.c:158 [inline] > do_el0_svc+0x120/0x260 arch/arm64/kernel/syscall.c:227 > el0_svc+0x20/0x2c arch/arm64/kernel/entry-common.c:367 > el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383 > el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670 > > Freed by task 4399: > stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121 > kasan_save_stack mm/kasan/common.c:48 [inline] > kasan_set_track+0x38/0x6c mm/kasan/common.c:56 > kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:355 > __kasan_slab_free+0x124/0x150 mm/kasan/common.c:422 > kasan_slab_free+0x10/0x1c mm/kasan/common.c:431 > slab_free_hook mm/slub.c:1544 [inline] > slab_free_freelist_hook+0xb0/0x1ac mm/slub.c:1577 > slab_free mm/slub.c:3142 [inline] > kmem_cache_free+0xc4/0x268 mm/slub.c:3158 > radix_tree_node_rcu_free+0x60/0x6c lib/radix-tree.c:302 > rcu_do_batch+0x180/0x404 kernel/rcu/tree.c:2479 > rcu_core+0x3e0/0x410 kernel/rcu/tree.c:2714 > rcu_core_si+0xc/0x14 kernel/rcu/tree.c:2727 > __do_softirq+0x180/0x3e0 kernel/softirq.c:298 > > radix_tree_next_slot called by idr_for_each will traverse all slot > regardless of whether the slot is valid. And once the last valid slot > has been remove, we will try to free the node, and lead to a UAF. > > idr_destroy will do what we want. So, just stop call idr_remove in > io_unregister_personality to fix the problem. > > Reported-by: Hulk Robot > Signed-off-by: yangerkun > --- > fs/io_uring.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/io_uring.c b/fs/io_uring.c > index 92c25b5f1349..b462c2bf0f2c 100644 > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -8494,9 +8494,9 @@ static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id) > > static int io_remove_personalities(int id, void *p, void *data) > { > - struct io_ring_ctx *ctx = data; > + const struct cred *creds = p; > > - io_unregister_personality(ctx, id); > + put_cred(creds); > return 0; > } > > -- Pavel Begunkov